This invention relates generally to transformers and, more specifically, to low voltage, step-down transformers.
An ideal transformer isolates the input circuit from the output circuit, transforms the input voltage by a ratio of the number of turns in the windings, and is frequency independent. The output voltage is “stepped up” if the secondary coil has more turns than the primary coil. Similarly, if the secondary coil has fewer turns than the primary coil, the voltage will be “stepped down.” Additionally, the current will change in an inverse relation to the voltage. Specifically, if the voltage is stepped up across a transformer, the current will be decreased by the same proportion. The power output of a transformer equals the input power less any losses due to factors such as, but not limited to, magnetic imperfections, resistive heating of the transformer windings, and/or mechanical vibrations.
At least some known transformers are negatively affected through heat losses due to factors such as, but not limited to, the resistance of the windings and/or magnetic losses in the form of eddy currents. Additional heat within a transformer enclosure may be created by the connection circuitry. Heat may build up in connections between the coils and the input and output terminals due to natural resistance in the connections, interconnecting wires or cables, and/or any circuit protection devices such as, but not limited to, circuit breakers and/or fuses.
At least some known transformers are cooled using fans within the transformer enclosure. Such a cooling method may add to the expense of assembling and maintaining a transformer, and may also reduce the efficiency of the transformer, due to the additional moving parts and the power requirements. Moreover, such a cooling method may increase the noise associated with the normal operation of a transformer. The use of fans may also increase vibration of the transformer further affecting the efficiency due to mechanical vibration losses and noise generated by the vibrations against a supporting structure.